在eclipse下不能用javabean
小弟初学JSP,现在正在用eclipse
我按照书上和到网上找的资料配置好了开发环境后,JSP却一直不能正常运行,但又发现不了错误,只能来麻烦大家了,请帮帮忙
下面是我写的两个JAVABEAN和JSP文件
package wen;
import java.sql.*;
import java.io.*;
import java.util.Properties;
public class DBConnection
{
private static String driver;
private static String serverURL;
private static String username;
private static String password;
private static Connection conn = null;
private static Statement stmt = null;
private static String connectionFileName="connection.txt";
private String str;
private static Object initLock = new Object();
public Connection getConn() {
return conn;
}
public static Connection getConnection()
{
if(conn == null){
synchronized(initLock){
loadProperties();
try{
Class.forName(driver);
}
catch(ClassNotFoundException e){
System.out.println(e.toString());
}
try{
conn = DriverManager.getConnection(serverURL,username,password);
}
catch(SQLException e){
System.out.println(e.toString());
}
}
}
return conn;
}
public static void loadProperties(){
Properties connectionAdmin = new Properties();
System.out.println("连接配置文件:" + connectionFileName);
try{
connectionAdmin.load(new FileInputStream(connectionFileName));
}
catch(IOException e){
System.out.println("找不到文件" + connectionFileName);
System.out.println(e.toString());
}
driver = (String)connectionAdmin.get("driver");
serverURL = (String)connectionAdmin.get("serverURL");
username = (String)connectionAdmin.get("username");
password = (String)connectionAdmin.get("password");
}
public static ResultSet exec(String sql){
ResultSet rs = null;
try{
if(conn == null){
getConnection();
}
Statement stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
}catch(SQLException ex){
ex.printStackTrace();
}
return rs;
}
}
package wen;
import java.sql.*;
public class IndexBean {
public ResultSet getMoban(){
return DBConnection.exec("select * from MoBan");
}
}
<%@ page language="java" %>
<%@ page import="java.sql.*" %>
<jsp:useBean id="index" class="wen.IndexBean" scope="page"/>
<!DOCTYPE HTML PUBLIC "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
<title>Lomboz JSP</title>
</head>
<body bgcolor="#FFFFFF">
<%
ResultSet rs = index.getMoban();
while(rs.next()){
long mb_id = rs.getLong("MB_id");
String mb_name = rs.getString("MB_name");
%>
<table>
<tr>
<td><%=mb_name%></td>
</tr>
</table>
<%
}
%>
</body>
</html>
两天了,我一直找不出原因,麻烦大家帮忙看下问题在哪,这是报的错误
HTTP Status 500 -
--------------------------------------------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: /index1.jsp(3,0) The value for the useBean class attribute wen.IndexBean is invalid.
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:407)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:148)
org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1175)
org.apache.jasper.compiler.Node$UseBean.accept(Node.java:1117)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2164)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2214)
org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2220)
org.apache.jasper.compiler.Node$Root.accept(Node.java:457)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2164)
org.apache.jasper.compiler.Generator.generate(Generator.java:3322)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:199)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:296)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:277)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:265)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:564)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:299)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.23 logs.